UNDERCARRIAGE AR 3551294 - Caterpillar

Illustration 1 g01247493
This diagnostic code is recorded when the ECM detects that the current output of the alternator is below the expected level.The possible causes of this diagnostic code are listed:
A charging system component has failed.
The machine harness is open.
The ECM has failed. This is unlikely.Test Step 1. CHECK THE CHARGING SYSTEM AT HIGH IDLE
Start the engine. Run the engine at high idle.
Enter the diagnostic menu on the monitor. Observe the status of the diagnostic code.Expected Result:The diagnostic code is NO longer active.Results:
YES - The diagnostic code is NO longer active. Proceed to Test Step 2.
NO - The diagnostic code remains active. Proceed to Test Step 3.Test Step 2. CHECK THE CHARGING SYSTEM AT LOW IDLE
Start the engine. Run the engine at low idle.
Observe the status of the diagnostic code.Expected Result:The diagnostic code is NO longer active.Results:
YES - The diagnostic code is NO longer active. Watch for a recurrence.STOP
NO - The diagnostic code is active. The charging system is not charging at the proper level.Repair: If the engine low idle speed is too low, the alternator may not be producing the required output. Ensure that the engine low idle speed is correct and perform this test again. If the diagnostic code is still active, a charging system component may be defective. Check the charging system. See Special Instruction, REHS0354, "Charging System Troubleshooting" for more information.STOPTest Step 3. CHECK FOR AN OPEN CIRCUIT
Turn the disconnect switch and the key switch to the OFF position.
Disconnect the connector from the Gateway Worldview Module ECM. Disconnect wire 403-GN from the alternator "R" terminal.
Measure the resistance of wire 403-GN between the Gateway Worldview Module ECM harness connector contact 54 and the disconnected wire 403-GN at the alternator.Expected Result:The resistance should measure 5 ohms or less.Results:
YES - The resistance measures 5 ohms or less. The machine harness appears to be correct. Either the alternator is not working correctly or the ECM may be recording this diagnostic code incorrectly.Repair: Check the charging system. See Special Instruction, REHS0354, "Charging System Troubleshooting" for more information. If the charging system checks are correct, the ECM may have failed. It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. If the cause of the diagnostic code is NOT found, replace the ECM. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace".STOP
NO - The resistance measurement is greater than 5 ohms. Wire 403-GN between the ECM and the alternator is open in the machine harness. Repair: Refer to the machine electrical schematic and ensure that all harness connectors in the circuit are tight and in good condition. Repair the machine harness or replace the machine harness.STOP